Added fetch="select/join" attribute from Hibernate 3. fetch="select" is equivalent to outer-join="false", and fetch="join" is equivalent to outer-join="true".

This is experimental for now, and there are no tests using fetch attribute.


SVN: trunk@1733

Author: Sergey Koshcheyev

src/NHibernate/Cfg/Binder.cs

@@ -1111,24 +1111,44 @@ private static IType GetTypeFromXML( XmlNode node )
 
 		private static void InitOuterJoinFetchSetting( XmlNode node, IFetchable model )
 		{
-			XmlAttribute jfNode = node.Attributes[ "outer-join" ];
-			if( jfNode == null )
-			{
-				model.OuterJoinFetchSetting = OuterJoinFetchStrategy.Auto;
-			}
-			else
+			XmlAttribute fetchNode = node.Attributes[ "fetch" ];
+
+			OuterJoinFetchStrategy fetchStyle;
+
+			if( fetchNode == null )
 			{
-				string eoj = jfNode.Value;
-				if( "auto".Equals( eoj ) )
+				XmlAttribute jfNode = node.Attributes[ "outer-join" ];
+				if( jfNode == null )
 				{
-					model.OuterJoinFetchSetting = OuterJoinFetchStrategy.Auto;
+					fetchStyle = OuterJoinFetchStrategy.Auto;
 				}
 				else
 				{
-					model.OuterJoinFetchSetting = ( "true".Equals( eoj ) ) ?
-						OuterJoinFetchStrategy.Eager : OuterJoinFetchStrategy.Lazy;
+					// use old (HB 2.1) defaults if outer-join is specified
+					string eoj = jfNode.Value;
+					if( "auto".Equals( eoj ) )
+					{
+						// TODO: H3 has two special cases here, for many-to-many and one-to-one
+						fetchStyle = OuterJoinFetchStrategy.Auto;
+					}
+					else
+					{
+						bool join = "true".Equals( eoj );
+						fetchStyle = join ?
+							OuterJoinFetchStrategy.Join :
+							OuterJoinFetchStrategy.Select;
+					}
 				}
 			}
+			else
+			{
+				bool join = "join".Equals( fetchNode.Value );
+				fetchStyle = join ?
+					OuterJoinFetchStrategy.Join :
+					OuterJoinFetchStrategy.Select;
+			}
+
+			model.OuterJoinFetchSetting = fetchStyle;
 		}
 
 		private static void MakeIdentifier( XmlNode node, SimpleValue model, Mappings mappings )

src/NHibernate/FetchMode.cs

@@ -20,12 +20,17 @@ public enum FetchMode
 		/// </summary>
 		Default = 0,
 		/// <summary>
-		/// Fetch lazily.  Equivalent to <c>outer-join="false"</c>
+		/// Fetch eagerly, using a separate select. Equivalent to
+		/// <c>fetch="select"</c> (and <c>outer-join="false"</c>)
 		/// </summary>
-		Lazy = 1,
+		Select = 1,
 		/// <summary>
-		/// Fetch eagerly, using an outer join.  Equivalent to <c>outer-join="true"</c>
+		/// Fetch using an outer join.  Equivalent to
+		/// <c>fetch="join"</c> (and <c>outer-join="true"</c>)
 		/// </summary>
-		Eager = 2
+		Join = 2,
+
+		Lazy = Select,
+		Eager = Join
 	}
 }

src/NHibernate/Loader/OuterJoinLoader.cs

@@ -11,12 +11,19 @@
 
 namespace NHibernate.Loader
 {
-	/// <summary></summary>
+	// TODO: This is actually the same as enum FetchMode, except that
+	// the underlying values are different. There are instances in the code
+	// where an enum value is compared to 0 or -1, so I'm afraid to unify
+	// the two types. - Sergey K
 	public enum OuterJoinFetchStrategy
 	{
 		Lazy = -1,
 		Auto = 0,
-		Eager = 1
+		Eager = 1,
+
+		Default = Auto,
+		Join = Eager,
+		Select = Lazy
 	}
 
 	/// <summary>

src/NHibernate/nhibernate-mapping-2.0.xsd

@@ -15,6 +15,12 @@
 			<xs:enumeration value="false"/>
 		</xs:restriction>
 	</xs:simpleType>
+	<xs:simpleType name="fetchMode">
+		<xs:restriction base="xs:string">
+			<xs:enumeration value="select"/> <!-- equivalent to outer-join="false" -->
+			<xs:enumeration value="join"/> <!-- equivalent to outer-join="true" -->
+		</xs:restriction>
+	</xs:simpleType>
 	<xs:simpleType name="cascadeStyle">
 		<xs:annotation>
 			<xs:documentation>Rule as to how to operate on child objects (for more information, read topics about "persistence by reachability" or "transparent/transitive/cascading persistence")</xs:documentation>
@@ -63,6 +69,7 @@
 			</xs:annotation>
 		</xs:attribute>
 		<xs:attribute name="outer-join" type="outerJoinStrategy" use="optional"/>
+		<xs:attribute name="fetch" type="fetchMode" use="optional" />
 		<xs:attribute name="cascade" type="cascadeStyle" use="optional"/>
 		<xs:attribute name="where" type="xs:string" use="optional"/>
 		<xs:attribute name="inverse" type="xs:boolean" use="optional" default="false"/>
@@ -693,6 +700,7 @@
 			<xs:attribute name="column" type="xs:string"/>
 			<xs:attribute name="foreign-key" type="xs:string" use="optional"/>
 			<xs:attribute name="outer-join" type="outerJoinStrategy" default="auto"/>
+			<xs:attribute name="fetch" type="fetchMode" use="optional" />
 		</xs:complexType>
 	</xs:element>
 	<xs:element name="many-to-one">
@@ -709,6 +717,7 @@
 			<xs:attribute name="unique" type="xs:boolean" default="false"/>
 			<xs:attribute name="cascade" type="cascadeStyle"/>
 			<xs:attribute name="outer-join" type="outerJoinStrategy" default="auto"/>
+			<xs:attribute name="fetch" type="fetchMode" use="optional" />
 			<xs:attribute name="update" type="xs:boolean" default="true"/>
 			<xs:attribute name="insert" type="xs:boolean" default="true"/>
 			<xs:attribute name="foreign-key" type="xs:string" use="optional"/>
@@ -751,6 +760,7 @@
 			<xs:attribute name="class" type="xs:string"/>
 			<xs:attribute name="cascade" type="cascadeStyle"/>
 			<xs:attribute name="outer-join" type="outerJoinStrategy" default="auto"/>
+			<xs:attribute name="fetch" type="fetchMode" use="optional" />
 			<xs:attribute name="constrained" type="xs:boolean" default="false"/>
 			<xs:attribute name="foreign-key" type="xs:string" use="optional"/>
 			<xs:attribute name="property-ref" type="xs:string"/>